Active wear apparel or apparel designed to be worn in hot, humid environments are generally characterized as well suited to be worn during times when one is likely to be perspiring. Optimally, the active wear garment should have some moisture management capability, while still remaining comfortable, providing freedom of movement and being easy to care for. One of the prime factors for garment comfort when perspiring heavily is how well the garment transfers moisture away from the skin. Additionally, for greater comfort after periods of heavy perspiration, the garment should optimally feel dry next to the skin or inner garments.
Garments made from cotton fabric and other natural material fabrics (such as linen, wool, etc.) are generally absorbent, and continue to feel comfortable under conditions of very light perspiration. This is because the fabric absorbs the relatively small amount of moisture produced at these times, keeping the wearer feeling dry. However, under conditions of heavier perspiration, these fabrics feel wet, heavy and clingy, restricting movement and becoming uncomfortable to wear. Additionally, once these fabrics become wet, they take a long time to dry, and continue to feel damp and uncomfortable until they have fully dried. This dampness can have other undesirable effects on the wearer as well. For example, wet fabrics are known to have increased friction against skin. This dramatically increases the chafing and even blistering resulting from movement, commonly suffered during athletic activity. Also, a damp fabric tends to chill the wearer, once physical activity is stopped, through excessive evaporative cooling. This is most prominent when the dampness is in direct contact with the skin.
Fabrics made from untreated polyester, nylon and other synthetic materials do not readily absorb moisture, due to being hydrophobic. As a result, when untreated synthetic fabrics are worn under conditions of even moderate perspiration, moisture tends to build up on the skin, because the fabric does not absorb moisture. Thus, when wearing untreated garments made of synthetic fibers, water tends to bead up and become trapped on the inner surface of the garment, resulting in an extremely uncomfortable garment.
A variety of methods have been used to improve the moisture transfer characteristics of certain fabrics. One common method is to apply a hydrophilic finish to a hydrophobic fabric made from synthetic fibers, rendering it a wicking fabric. A second method of improving moisture transfer is to use various fabric construction techniques to create fabrics that are more hydrophobic on one surface and more hydrophilic on the other surface, leading to moisture transfer from the hydrophobic side to the hydrophilic side. A third method has been developed for cotton by treating one side of the fabric with a discontinuous hydrophobic coating, leaving untreated areas as “wicking channels” in the fabric, such as the method described in U.S. Pat. No. 7,008,887. In this case, the cellulosic fabric (which is naturally hydrophilic) is treated on the inside with a hydrophobic finish (such as a fluoropolymer, silicone, or waxy polymer). The finish is applied in a discontinuous pattern, such that “wicking channels” (i.e., untreated regions of fabric) are formed. Moisture is absorbed into the untreated wicking channel regions and then wicks to the other areas of the garment to enhance evaporation. However, wicking channels will remain wet and in contact with the skin, which is uncomfortable to the wearer.
A need remains for fabrics having improved moisture transfer capability, particularly for active wear where the garment can otherwise become soaked with sweat.